And because most of us use our phones more than our PCs, mobile malware can be more dangerous than the kind you’ll find on desktops. Tap or click here to see a terrifying mobile malware that cybercriminals can rent. Android users now have another security threat to worry about: A dangerous ransomware that locks the entire operating system. If this gets on your phone, you won’t be able to make calls, send texts, or browse the web at all! Here’s how it’s spreading.

Don’t let your phone get locked

Security researchers at Microsoft have announced the discovery of a new strain of ransomware targeting Android users. In a bulletin posted to Microsoft’s security blog, the company outlined the threat posed by AndroidOS/MalLocker.B, which is capable of completely locking phones and preventing their use. Infection occurs through uncertified apps and attachments posted to online forums and third-party app stores. Once a phone is infected, all a user needs to do is press the home button to trigger the ransomware. When the ransomware springs to life, it locks the entire phone and flashes a fake law enforcement alert that says the victim committed a crime. If you want your phone back, you have to pay the fine. It’s just like the ransomware you see on PCs. Tap or click here to see how ransomware shut down a hospital network and potentially cost patients their lives.

Annoying ads are all over Android

Android users have more than just ransomware to worry about right now. A separate security alert from researchers at WhiteOps discovered a batch of more than 240 malicious Android apps that spam your phone with advertisements without permission. The apps appeared like normal Google Play downloads, and all of them managed to reach a combined 15 million installs. Most of the apps were game-related, which means kids were more likely to install them. What sets these 240 apps apart is how it displayed the apps “out of context.” This just means the ads would pop up in different apps than the ones serving them. This could have been done to trick victims into deleting the wrong apps when trying to clean up their phones. If you want to know if any of these apps reached your phone, WhiteOps has the complete list. Tap or click here to see all of the apps causing popups for Android users.

What can I do to protect my phone from these malware apps?

Let’s get the good news out of the way: The ransomware detected by Microsoft doesn’t appear to have been found in any Google Play apps. This means that you’ll be safe from that attack as long as you avoid third-party app stores and download forums. This is just sound advice in general. Third-party app stores are filled with malware!. Tap or click here to see some of the malware you can find on third-party app stores. As for the 240+ apps with malicious ads, it’s up to victims to delete them from their phones. Many of these apps are still available on Google Play — which means it’s time to scan your phone carefully if you’re getting pop-ups out of the blue. To uninstall any of these apps, open Settings and tap the Apps menu. Scroll through your apps until you find any entries on the list from WhiteOps. Tap on them to uninstall and remove them. For more peace of mind, you can also reformat and erase your phone. Tap or click here to see how to perform a factory reset on your Android phone. Here are some basic tips to help keep your Android phone safe from malware:

Avoid visiting any app stores other than Google Play.When downloading Google Play apps, stick to well-known developers as much as possible. If you want to try something new, read reviews carefully to make sure it’s not a scam.Don’t click on links or attachments sent to you by email or text. You might end up on phishing sites that host malware.If someone you know sends you an email or text with a link, check with them personally to make sure they actually sent it.

And while you’re at it, keep checking your phone for malware on a regular basis. You never know if something was hiding in that Google Play app you downloaded on a whim. Tap or click here to see the latest batch of malware found on Google Play.